The present invention relates generally to tape recording techniques and apparatus and to systems for controlling the tape travel therein. More particularly, the invention relates to a tape travel control system suitable for stopping the tape travel at a desired position for recording on a tape.
In general, there are instances wherein only desired program portions are selectively extracted from a recorded tape and the portions are then joined to produce a single recorded tape which has been edited. In such an editing system, an apparatus reproduces a pre-recorded tape on which the signals to be edited have been recorded and an apparatus re-records the reproduced portions, on an unrecorded tape. The signals which have been thus selectively reproduced by the reproducing apparatus are used to make a new recording.
In this editing process, the first step comprises seeking out the first desired recording portions in the pre-recorded tape as this tape is being reproduced in the reproducing apparatus and stopping the tape at the starting position of this desired recorded portion. Next, as this first desired recorded portion is being reproduced by the reproducing apparatus, the reproduced signal is re-recorded on a previously unrecorded tape by means of the recording apparatus. When this re-recording of the first desired recorded portion ends, the recording apparatus is once again stopped.
Then, as the above mentioned pre-recorded tape is reproduced, a second desired recorded portion in this tape is sought out. This tape is stopped at the starting point of this second desired recorded portion. Next, as this second desired recorded portion is reproduced by the reproducing apparatus, the reproduced signal is recorded as a continuation to the above mentioned first recorded signal by means of the recording apparatus. By repeating these steps thereafter, a recorded tape is obtained on which a plurality of desired recorded information sections have been edited and re-recorded in the recording apparatus.
For a recorded video signal, the step of seeking out each of the above mentioned desired recorded portions in the reproducing apparatus is carried out by reproducing the tape, supplying the resulting reproduced signal to a monitor television receiver, and observing the reproduced picture. To stop the tape at the starting point of the desired recorded portion on the tape, the monitor television receiver is observed. At the instant when the beginning of the reproduction of the desired recorded information is detected, the tape is stopped.
In actual practice, however, the arrival at the desired recorded portion cannot be detected unless the reproduction of this desired recorded portion has already begun. Even if the tape travel is stopped instantaneously, the leading position at the start of the desired recorded portion will have already passed by. In actual practice, furthermore, there is a time delay from the instant at which the operator detects the start of the reproduction of the desired recorded portion to the instant at which he reacts and carries out the manipulation for stopping the tape travel. Still another difficulty is that, because the traveling tape and related parts have momentum, the tape travel will not stop instantaneously even if the reproducing apparatus is instantaneously placed in its stop mode. Consequently, the tape stops at a position which is separated (advanced in the forward direction) from the leading point at the start of the desired recorded portion. Particularly when the tape is traveling at high speed, in order to seek out the desired recorded portions in a short time, this positional separation becomes large.
Accordingly, in order to stop the tape at the desired starting point, a manipulative procedure comprises driving the tape at high speed in the forward direction, stopping the tape travel when the starting point of the desired recorded portion has passed by, thereafter driving the tape at low speed in the reverse direction to return the tape through the distance which it passed in the forward direction, and then stopping the tape at the correct starting point. Furthermore, in driving the tape in the reverse direction, the tape may again overshoot the starting point, in which case it is necessary to drive the tape at low speed in the forward direction.
In known apparatus, the manipulation part for changing the tape travel direction and for changing the tape travel speed have been independent of each other. There has been no mutual interrelation therebetween whatsoever. For this reason, in order to stop the tape at the correct starting point, it has been necessary to separate the manipulation for changing the tape travel direction and the manipulation for changing the tape travel speed. This procedure has been unsatisfactory because it is troublesome, requires time, and requires a skilled operator.